dft: make ScanPin copyable, remove per-chain enables

misc. gardening to the abseil codex

src/dft/README.md

@@ -28,7 +28,6 @@ set_dft_config
     [-max_length <int>]
     [-max_chains <int>]
     [-clock_mixing <string>]
-    [-scan_enable_mode <string>]
     [-scan_enable_name_pattern <string>]
     [-scan_in_name_pattern <string>]
     [-scan_out_name_pattern <string>]
@@ -42,10 +41,9 @@ set_dft_config
 | `-max_chains` | The maximum number of scan chains that will be generated. This takes priority over `max_length`,
 in `no_mix` clock mode it specifies a maximum number of chains per clock-edge pair. |
 | `-clock_mixing` | How architect will mix the scan flops based on the clock driver. `no_mix`: Creates scan chains with only one type of clock and edge. This may create unbalanced chains. `clock_mix`: Creates scan chains mixing clocks and edges. Falling edge flops are going to be stitched before rising edge. |
-| `-scan_enable_mode` | Experimental: how the scan chain enable signals will be created/assigned by the scan chain stitcher. `global`: All scan chains use the same enable signal. `per_chain`: Each scan chain gets assigned or created its own scan enanle. The default is `global`.  |
-| `-scan_enable_name_pattern` | A format pattern with exactly one set of braces (`{}`) to use to find or create scan enable drivers during scan chain stitching. The braces will be replaced with the chain's ordinal number (starting at `0`) if `-scan_enable_mode` is set to `per_chain`, otherwise, all will share `0`. If an un-escaped forward slash (`/`) is found, instead of searching for and/or creating a top-level port, an instance's pin will be searched for instead where the part of the string preceding the `/` is interpreted as the instance name and part succeeding it will be interpreted as the pin's name. |
-| `-scan_in_name_pattern` | A format pattern with exactly one set of braces (`{}`) to use to find or create scan in drivers during scan chain stitching. The braces will be replaced with the chain's ordinal number (starting at `0`). If an un-escaped forward slash (`/`) is found, instead of searching for and/or creating a top-level port, an instance's pin will be searched for instead where the part of the string preceding the `/` is interpreted as the instance name and part succeeding it will be interpreted as the pin's name. |
-| `-scan_out_name_pattern` | A format pattern with exactly one set of braces (`{}`) to use to find or create scan in loads during scan chain stitching. The braces will be replaced with the chain's ordinal number (starting at `0`). If an un-escaped forward slash (`/`) is found, instead of searching for and/or creating a top-level port, an instance's pin will be searched for instead where the part of the string preceding the `/` is interpreted as the instance name and part succeeding it will be interpreted as the pin's name. |
+| `-scan_enable_name_pattern` | A format pattern with one or less set of braces (`{}`) to use to find or create scan enable drivers during scan chain stitching. The braces, if found, will be set to `0` as DFT architectures typically use a single shift-enable for all scan chains. If an un-escaped forward slash (`/`) is found, instead of searching for and/or creating a top-level port, an instance's pin will be searched for instead where the part of the string preceding the `/` is interpreted as the instance name and part succeeding it will be interpreted as the pin's name. |
+| `-scan_in_name_pattern` | A format pattern with one or less braces (`{}`) to use to find or create scan in drivers during scan chain stitching. The braces will be replaced with the chain's ordinal number (starting at `0`). If an un-escaped forward slash (`/`) is found, instead of searching for and/or creating a top-level port, an instance's pin will be searched for instead where the part of the string preceding the `/` is interpreted as the instance name and part succeeding it will be interpreted as the pin's name. |
+| `-scan_out_name_pattern` | A format pattern with one or less braces (`{}`) to use to find or create scan in loads during scan chain stitching. The braces will be replaced with the chain's ordinal number (starting at `0`). If an un-escaped forward slash (`/`) is found, instead of searching for and/or creating a top-level port, an instance's pin will be searched for instead where the part of the string preceding the `/` is interpreted as the instance name and part succeeding it will be interpreted as the pin's name. |
 
 ### Report DFT Config
 

src/dft/src/Dft.cpp

@@ -46,7 +46,9 @@
 #include "odb/db.h"
 #include "utl/Logger.h"
 
+namespace {
 constexpr char kDefaultPartition[] = "default";
+}  // namespace
 
 namespace dft {
 
@@ -122,14 +124,14 @@ void Dft::insertDft()
   odb::dbBlock* db_block = db_->getChip()->getBlock();
   odb::dbDft* db_dft = db_block->getDft();
 
-  for (auto& chain : scan_chains) {
+  for (const auto& chain : scan_chains) {
     odb::dbScanChain* db_sc = odb::dbScanChain::create(db_dft);
     db_sc->setName(chain->getName());
     odb::dbScanPartition* db_part = odb::dbScanPartition::create(db_sc);
     db_part->setName(kDefaultPartition);
     odb::dbScanList* db_scanlist = odb::dbScanList::create(db_part);
 
-    for (auto& scan_cell : chain->getScanCells()) {
+    for (const auto& scan_cell : chain->getScanCells()) {
       std::string inst_name(scan_cell->getName());
       odb::dbInst* db_inst = db_block->findInst(inst_name.c_str());
       odb::dbScanInst* db_scaninst = db_scanlist->add(db_inst);
@@ -140,17 +142,23 @@ void Dft::insertDft()
           {.scan_in = scan_in_term, .scan_out = scan_out_term});
     }
 
-    ScanDriver sc_enable_driver = chain->getScanEnable();
-    ScanDriver sc_in_driver = chain->getScanIn();
-    ScanLoad sc_out_load = chain->getScanOut();
-
-    std::visit(
-        [&](auto&& sc_enable_term) { db_sc->setScanEnable(sc_enable_term); },
-        sc_enable_driver.getValue());
-    std::visit([&](auto&& sc_in_term) { db_sc->setScanIn(sc_in_term); },
-               sc_in_driver.getValue());
-    std::visit([&](auto&& sc_out_term) { db_sc->setScanOut(sc_out_term); },
-               sc_out_load.getValue());
+    std::optional<ScanDriver> sc_enable_driver = chain->getScanEnable();
+    std::optional<ScanDriver> sc_in_driver = chain->getScanIn();
+    std::optional<ScanLoad> sc_out_load = chain->getScanOut();
+
+    if (sc_enable_driver.has_value()) {
+      std::visit(
+          [&](auto&& sc_enable_term) { db_sc->setScanEnable(sc_enable_term); },
+          sc_enable_driver.value().getValue());
+    }
+    if (sc_in_driver.has_value()) {
+      std::visit([&](auto&& sc_in_term) { db_sc->setScanIn(sc_in_term); },
+                 sc_in_driver.value().getValue());
+    }
+    if (sc_out_load.has_value()) {
+      std::visit([&](auto&& sc_out_term) { db_sc->setScanOut(sc_out_term); },
+                 sc_out_load.value().getValue());
+    }
   }
 }
 

src/dft/src/architect/ScanChain.cpp

@@ -119,30 +119,30 @@ const std::string& ScanChain::getName() const
   return name_;
 }
 
-ScanDriver ScanChain::getScanIn() const
+std::optional<ScanDriver> ScanChain::getScanIn() const
 {
-  return ScanDriver(scan_in_);
+  return scan_in_;
 }
-ScanDriver ScanChain::getScanEnable() const
+std::optional<ScanDriver> ScanChain::getScanEnable() const
 {
-  return ScanDriver(scan_enable_);
+  return scan_enable_;
 }
-ScanLoad ScanChain::getScanOut() const
+std::optional<ScanLoad> ScanChain::getScanOut() const
 {
-  return ScanLoad(scan_out_);
+  return scan_out_;
 }
 
-void ScanChain::setScanIn(const ScanDriver& signal)
+void ScanChain::setScanIn(const std::optional<ScanDriver>& signal)
 {
-  scan_in_ = signal.getValue();
+  scan_in_ = signal;
 }
-void ScanChain::setScanEnable(const ScanDriver& signal)
+void ScanChain::setScanEnable(const std::optional<ScanDriver>& signal)
 {
-  scan_enable_ = signal.getValue();
+  scan_enable_ = signal;
 }
-void ScanChain::setScanOut(const ScanLoad& signal)
+void ScanChain::setScanOut(const std::optional<ScanLoad>& signal)
 {
-  scan_out_ = signal.getValue();
+  scan_out_ = signal;
 }
 
 }  // namespace dft

src/dft/src/architect/ScanChain.hh

@@ -86,13 +86,13 @@ class ScanChain
   const std::string& getName() const;
 
   // For stitchers
-  ScanDriver getScanIn() const;
-  ScanDriver getScanEnable() const;
-  ScanLoad getScanOut() const;
+  std::optional<ScanDriver> getScanIn() const;
+  std::optional<ScanDriver> getScanEnable() const;
+  std::optional<ScanLoad> getScanOut() const;
 
-  void setScanIn(const ScanDriver& signal);
-  void setScanEnable(const ScanDriver& signal);
-  void setScanOut(const ScanLoad& signal);
+  void setScanIn(const std::optional<ScanDriver>& signal);
+  void setScanEnable(const std::optional<ScanDriver>& signal);
+  void setScanOut(const std::optional<ScanLoad>& signal);
 
  private:
   std::string name_;
@@ -106,11 +106,9 @@ class ScanChain
   uint64_t bits_;
 
   // After stitching: store input/output bterms/iterms
-  std::variant<odb::dbBTerm*, odb::dbITerm*> scan_in_ = (odb::dbBTerm*) nullptr;
-  std::variant<odb::dbBTerm*, odb::dbITerm*> scan_out_
-      = (odb::dbBTerm*) nullptr;
-  std::variant<odb::dbBTerm*, odb::dbITerm*> scan_enable_
-      = (odb::dbBTerm*) nullptr;
+  std::optional<ScanDriver> scan_in_;
+  std::optional<ScanLoad> scan_out_;
+  std::optional<ScanDriver> scan_enable_;
 };
 
 }  // namespace dft

src/dft/src/config/ScanStitchConfig.cpp

@@ -37,7 +37,7 @@
 namespace dft {
 
 void ScanStitchConfig::setEnableNamePattern(
-    std::string_view& enable_name_pattern)
+    std::string_view enable_name_pattern)
 {
   enable_name_pattern_ = enable_name_pattern;
 }
@@ -46,7 +46,7 @@ std::string_view ScanStitchConfig::getEnableNamePattern() const
   return enable_name_pattern_;
 };
 
-void ScanStitchConfig::setInNamePattern(std::string_view& in_name_pattern)
+void ScanStitchConfig::setInNamePattern(std::string_view in_name_pattern)
 {
   in_name_pattern_ = in_name_pattern;
 };
@@ -55,7 +55,7 @@ std::string_view ScanStitchConfig::getInNamePattern() const
   return in_name_pattern_;
 };
 
-void ScanStitchConfig::setOutNamePattern(std::string_view& out_name_pattern)
+void ScanStitchConfig::setOutNamePattern(std::string_view out_name_pattern)
 {
   out_name_pattern_ = out_name_pattern;
 };
@@ -64,32 +64,9 @@ std::string_view ScanStitchConfig::getOutNamePattern() const
   return out_name_pattern_;
 };
 
-void ScanStitchConfig::setEnableMode(ScanStitchConfig::EnableMode enable_mode)
-{
-  enable_mode_ = enable_mode;
-}
-ScanStitchConfig::EnableMode ScanStitchConfig::getEnableMode() const
-{
-  return enable_mode_;
-}
-
-std::string_view ScanStitchConfig::EnableModeName(
-    ScanStitchConfig::EnableMode enable_mode)
-{
-  switch (enable_mode) {
-    case ScanStitchConfig::EnableMode::Global:
-      return "Global";
-    case ScanStitchConfig::EnableMode::PerChain:
-      return "Per-Chain";
-    default:
-      return "ScanStitchConfig::EnableMode missing case";
-  }
-}
-
 void ScanStitchConfig::report(utl::Logger* logger) const
 {
   logger->report("Scan Stitch Config:");
-  logger->report("- Enable Mode: '{}'", EnableModeName(enable_mode_));
   logger->report("- Scan Enable Name Pattern: '{}'", enable_name_pattern_);
   logger->report("- Scan In Name Pattern: '{}'", in_name_pattern_);
   logger->report("- Scan Out Name Pattern: '{}'", out_name_pattern_);

src/dft/src/config/ScanStitchConfig.hh

@@ -38,34 +38,22 @@ namespace dft {
 class ScanStitchConfig
 {
  public:
-  enum class EnableMode
-  {
-    Global = 0,
-    PerChain
-  };
-
-  static std::string_view EnableModeName(EnableMode enable_mode);
-
-  void setEnableNamePattern(std::string_view& enable_name_pattern);
+  void setEnableNamePattern(std::string_view enable_name_pattern);
   std::string_view getEnableNamePattern() const;
 
-  void setInNamePattern(std::string_view& in_name_pattern);
+  void setInNamePattern(std::string_view in_name_pattern);
   std::string_view getInNamePattern() const;
 
-  void setOutNamePattern(std::string_view& out_name_pattern);
+  void setOutNamePattern(std::string_view out_name_pattern);
   std::string_view getOutNamePattern() const;
 
-  void setEnableMode(EnableMode enable_mode);
-  EnableMode getEnableMode() const;
-
   // Prints using logger->report the config used by Scan Stitch
   void report(utl::Logger* logger) const;
 
  private:
   std::string enable_name_pattern_ = "scan_enable_{}";
   std::string in_name_pattern_ = "scan_in_{}";
   std::string out_name_pattern_ = "scan_out_{}";
-  EnableMode enable_mode_ = EnableMode::Global;
 };
 
 }  // namespace dft

src/dft/src/dft.i

@@ -54,27 +54,6 @@ utl::Logger* getLogger()
 
 %include "../../Exception.i"
 
-// Enum: dft::ResetActiveEdge
-%typemap(typecheck) dft::ResetActiveEdge {
-  char *str = Tcl_GetStringFromObj($input, 0);
-    if (strcasecmp(str, "LOW") == 0) {
-    $1 = 1;
-  } else if (strcasecmp(str, "HIGH") == 0) {
-    $1 = 1;
-  } else {
-    $1 = 0;
-  }
-}
-
-%typemap(in) dft::ResetActiveEdge {
-  char *str = Tcl_GetStringFromObj($input, 0);
-  if (strcasecmp(str, "LOW") == 0) {
-    $1 = dft::ResetActiveEdge::Low;
-  } else /* other values eliminated in typecheck */ {
-    $1 = dft::ResetActiveEdge::High;
-  };
-}
-
 // Enum: dft::ClockEdge
 %typemap(typecheck) dft::ClockEdge {
   char *str = Tcl_GetStringFromObj($input, 0);
@@ -117,27 +96,6 @@ utl::Logger* getLogger()
   };
 }
 
-// Enum: dft::EnableMode
-%typemap(typecheck) dft::ScanStitchConfig::EnableMode {
-  char *str = Tcl_GetStringFromObj($input, 0);
-    if (strcasecmp(str, "GLOBAL") == 0) {
-    $1 = 1;
-  } else if (strcasecmp(str, "PER_CHAIN") == 0) {
-    $1 = 1;
-  } else {
-    $1 = 0;
-  }
-}
-
-%typemap(in) dft::ScanStitchConfig::EnableMode {
-  char *str = Tcl_GetStringFromObj($input, 0);
-  if (strcasecmp(str, "GLOBAL") == 0) {
-    $1 = dft::ScanStitchConfig::EnableMode::Global;
-  } else /* other values eliminated in typecheck */ {
-    $1 = dft::ScanStitchConfig::EnableMode::PerChain;
-  };
-}
-
 %inline
 %{
 
@@ -171,13 +129,8 @@ void set_dft_config_clock_mixing(dft::ScanArchitectConfig::ClockMixing clock_mix
   getDft()->getMutableDftConfig()->getMutableScanArchitectConfig()->setClockMixing(clock_mixing);
 }
 
-void set_dft_config_scan_enable_mode(dft::ScanStitchConfig::EnableMode enable_mode)
-{
-  getDft()->getMutableDftConfig()->getMutableScanStitchConfig()->setEnableMode(enable_mode);
-}
-
 void set_dft_config_scan_signal_name_pattern(const char* signal_ptr, const char* pattern_ptr) {
-  auto config = getDft()->getMutableDftConfig()->getMutableScanStitchConfig();
+  dft::ScanStitchConfig* config = getDft()->getMutableDftConfig()->getMutableScanStitchConfig();
   std::string_view signal(signal_ptr), pattern(pattern_ptr);
 
   if (signal == "scan_in") {

src/dft/src/dft.tcl

@@ -73,7 +73,6 @@ proc insert_dft { args } {
 sta::define_cmd_args "set_dft_config" { [-max_length max_length]
                                         [-max_chains max_chains]
                                         [-clock_mixing clock_mixing]
-                                        [-scan_enable_mode mode]
                                         [-scan_enable_name_pattern scan_enable_name_pattern]
                                         [-scan_in_name_pattern scan_in_name_pattern]
                                         [-scan_out_name_pattern scan_out_name_pattern]
@@ -84,7 +83,6 @@ proc set_dft_config { args } {
       -max_length
       -max_chains
       -clock_mixing
-      -scan_enable_mode
       -scan_enable_name_pattern
       -scan_in_name_pattern
       -scan_out_name_pattern
@@ -110,10 +108,6 @@ proc set_dft_config { args } {
     dft::set_dft_config_clock_mixing $clock_mixing
   }
 
-  if { [info exists keys(-scan_enable_mode)] } {
-    dft::set_dft_config_scan_enable_mode $keys(-scan_enable_mode)
-  }
-
   foreach {flag signal} {
     -scan_enable_name_pattern "scan_enable"
     -scan_in_name_pattern "scan_in"